const { src, dest, parallel, series, watch } = require('gulp')

const del = require('del') 

const loadPlugins = require('gulp-load-plugins')
const plugins = loadPlugins()

const browserSync = require('browser-sync')
const bs = browserSync.create()

const data = {
    menus: [
      {
        name: 'Home',
        icon: 'aperture',
        link: 'index.html'
      },
      {
        name: 'About',
        link: 'about.html'
      }
    ],
    pkg: require('./package.json'),
    date: new Date()
}

const style = () => {
  return src('src/assets/styles/*.scss', { base: 'src' })
    .pipe(plugins.sass({ outputStyle: 'expanded' }))
    .pipe(dest('temp'))
    .pipe(bs.reload({ stream: true }))
}

const script = () => {
    return src('src/assets/scripts/*.js', { base: 'src' })
      .pipe(plugins.babel({ presets: ['@babel/preset-env']}))
      .pipe(dest('temp'))
      .pipe(bs.reload({ stream: true }))
}

const page = () => {
    return src('src/*.html', { base:'src' })
      .pipe(plugins.swig({ data, defaults: { cache: false } }))
      .pipe(dest('temp'))
      .pipe(bs.reload({ stream: true }))
}

const image = () => {
    return src('src/assets/images/**', { base:'src' })
      .pipe(plugins.imagemin())
      .pipe(dest('dist'))
}

const font = () => {
    return src('src/assets/fonts/**', { base:'src' })
      .pipe(plugins.imagemin())
      .pipe(dest('dist'))
}

const extra = () => {
    return src('public/**', { base: 'public' })
      .pipe(dest('dist'))
}

const clean = () => {
    return del(['dist', 'temp'])
}

const serve = () => {
    watch('src/assets/styles/*.scss', style)
    watch('src/assets/scripts/*.js', script)
    watch('src/*.html', page)

    watch([
        'src/assets/images/**',
        'src/assets/fonts/**',
        'public/**'
      ], bs.reload)

    bs.init({
      server: { 
        baseDir:['temp', 'src', 'public'], 
        routes: {
          '/node_modules': 'node_modules'
        }
      },
      notify: false
    })
}

const useref = () => {
    return src('temp/*.html', { base: 'temp' })
      .pipe(plugins.useref({ searchPath: ['temp', '.']}))
      .pipe(plugins.if(/\.js$/, plugins.uglify()))
      .pipe(plugins.if(/\.css$/, plugins.cleanCss()))
      .pipe(plugins.if(/\.html$/, plugins.htmlmin({ 
        collapseWhitespace: true,
        minifyCSS: true,
        minifyJS: true
        })))
      .pipe(dest('dist'))
}

const compile = parallel(style, script, page)

const develop = series(compile, serve)

//上线之前执行
const build = series(clean, parallel(series(compile, useref), extra, image, font))

module.exports = {
    clean,
    build,
    develop,
}

